The present invention relates generally to suspension mechanisms for vehicles. More particularly, the present invention relates to suspension mechanisms utilized in snowmobile suspensions.
Snowmobiling is a popular recreational activity in areas which receive snow during the winter. Local trail systems have been developed in areas in which snowmobiling is popular. It is not uncommon for a snowmobiler to cover one hundred (100) miles in a single outing. Unfortunately, it is also not uncommon for snowmobile trails to be in rough condition due to the volume of snowmobile traffic on weekends and other times when a large number of snowmobilers are using the trail. The trail conditions encountered by a snowmobiler can vary from a freshly groomed trail to sections of small washboard bumps to sections of very large bumps. The snowmobiler may also cross roads, cross icy lakes, or venture off the trail into powder snow all in a single excursion.
In order to fully enjoy the sport of snowmobiling, snowmobilers require a snowmobile suspension which gives them good ride quality and good control of the snowmobile. Ideally, this suspension mechanism should be adjustable to accommodate changing trail conditions. Because snowmobile suspension mechanisms are subjected to repeated shocks and intense vibration along with exposure to water, ice, snow, salt and dirt, it is important that snowmobile suspension mechanisms be very durable.
The present invention relates generally to suspension mechanisms for vehicles. More particularly, the present invention relates to suspension mechanisms utilized in snowmobile suspensions.
A suspension mechanism for a snowmobile comprising a pair of elongated side rails connected together by a plurality of supports to define a slide frame. A rear suspension mechanism is attached to the slide frame which includes an air spring. The air spring having a first end and second end, the first end of said air spring being pivotally connected to the chassis of the snowmobile. A cradle pivotally connected to the slide frame. The second end of the air spring mounted in the cradle. The cradle is designed such that the pivot point of the cradle is located below the point at which the air spring is connected to the cradle. This mounting structure allows the cradle to rotate to accommodate changes in the angular orientation of the air spring.
A snowmobile in accordance with the present invention includes a seat to accommodate a snowmobile operator, a steering arrangement, and a control panel. In a presently preferred embodiment, both the steering arrangement and the control panel are located where they will be easily accessible to the snowmobile operator. The major components of snowmobile include; a pair of skis each having a ski suspension mechanism, a hood, a track, a chassis, and a rear suspension.
In a presently preferred embodiment, the rear suspension includes a slide frame, which supports the track along its length. The slide frame includes a left slide and a right slide which are connected by a plurality of cross members. The left slide and the right slide are also connected by a rear axle which supports a plurality of idler wheels. A plurality of bogie wheels may also be pivotably attached to slide frame.
In a presently preferred embodiment, one or more suspension mechanisms are coupled to the slide frame. A suspension mechanism in accordance with the present invention comprises a suspension arm which is adapted to be pivotably coupled to the chassis of a snowmobile proximate a first end of the suspension arm. The suspension mechanism may also include at least one arm having a first end which is pivotably coupled to the first end of the suspension arm. A second end of the at least one swing arm is pivotably coupled to the slide frame. A pivot arm having a first end may be pivotably coupled to the suspension arm proximate a second end thereof. In a presently preferred embodiment, the pivot arm includes a pivot axle and a second end. The second end of pivot arm is pivotably coupled to the slide frame.
The suspension mechanism also includes an air spring having a first end and a second end. The first end of air spring is seated against a cradle which is pivotably coupled to the suspension arm. The second end of the air spring is seated against a seating portion of the slide frame. In a presently preferred embodiment, a cradle axle is fixed to cradle.
The suspension mechanism may also include a first arm and a second arm. The first arm being fixed to cradle axle and the second arm being fixed to pivot axle. A link having a first end and a second end is disposed between the first arm and the second arm. In a presently preferred embodiment, the first end of the link is pivotably coupled to the first arm and the second end of link is pivotably coupled to the second arm.
In a presently preferred embodiment, the first arm, the second arm, and the link cooperate to assure that the first end of the air spring remains generally parallel to the second end of air spring. This mechanism assures that the air spring will be loaded along it""s longitudinal axis. This arrangement also dramatically reduces the likelihood that the air spring will buckle.
In a presently preferred embodiment, the air spring serves to support at least some of the weight of the snowmobile. When the snowmobile encounters a bump air spring may deflect. The spring and a shock absorber may act to dampen the movement of the suspension mechanism. In a method in accordance with the present invention, the stiffness of the suspension mechanism may be adjusted by raising or lower the pressure of the fluid in the chamber of air spring.
A suspension system in accordance with the present invention may include a means for adjusting the pressure inside the chamber of the air spring. One embodiment of a suspension system in accordance with the present invention includes a front suspension mechanism having a front air spring and a rear suspension mechanism a having a rear air spring. The snowmobile operator may actuate one or more switches to selectively adjust the pressure in the chambers of the front and rear air springs to vary the stiffness of the front and rear suspension mechanisms.